Built-in battery device of electric bicycle

Abstract

A built-in battery device of an electric bicycle, including a seat post connected to a base, the base is connected to a saddle, and a battery pack is arranged in the seat post, and the cross section of the seat post is an curved surface with a narrow front end and a wide rear end; the battery pack is disposed in a stack, and on the cross section of the seat post, the number of built-in batteries in a single row at the rear end is more than that in a single row at the front end. The vertical spacing of the battery pack is provided with a connection bracket which is fixedly connected to the head and the tail of the multi-layer batteries. The electric bicycle has the advantages of reasonable space utilization, beautiful appearance, convenient assembly and small wind resistance.

What is claimed is: 
     
         1 . A built-in battery device of electric bicycle, comprising a seat post ( 1 ) connected to a base ( 2 ), the base is connected to a saddle ( 3 ), and a battery pack ( 4 ) is arranged in the seat post, wherein a cross section of the seat post is an curved surface with a narrow front end ( 11 ) and a wide rear end ( 12 ); the battery pack is disposed in a stack, a number of built-in batteries arranged in a single row at the rear end is more than a number of batteries arranged in a single row at the front end on the cross section of seat post; a vertical spacing of the battery pack is provided with a connection bracket ( 42 ), and a head and a tail of multi-layer batteries are fixedly connected by the connection bracket. 
     
     
         2 . The built-in battery device of the electric bicycle according to  claim 1 , wherein single batteries ( 41 ) of the battery pack are arranged in three rows as a front row, a middle row and a rear row on the cross section of the seat post. 
     
     
         3 . The built-in battery device of the electric bicycle according to  claim 2 , wherein a number of single batteries of the battery pack is one in the front row, two in the middle row and two in the rear row. 
     
     
         4 . The built-in battery device of the electric bicycle according to  claim 1 , wherein a boss ( 421 ) and a through hole ( 422 ) are arranged on the connection bracket; when two connection brackets are in a docking position, the boss is matched with the through hole. 
     
     
         5 . The built-in battery device of the electric bicycle according to  claim 1 , wherein the connection bracket is provided with a plurality of ring holes, and an edge of each of the plurality of ring holes is provided with at least one clamping portion ( 423 ), and an inner diameter of the clamping portion is smaller than an inner diameter of the ring hole position. 
     
     
         6 . The built-in battery device of the electric bicycle according to  claim 1 , wherein a protective cover ( 5 ) is fixedly arranged at a bottom of the seat post. 
     
     
         7 . The built-in battery device of the electric bicycle according to  claim 6 , wherein an elastic seal ring ( 6 ) is arranged at edges where the protective cover and the seat post are in contact. 
     
     
         8 . The built-in battery device of the electric bicycle according to  claim 1 , wherein the seat post is inserted into a middle tube ( 7 ), and a cross-sectional shape of the middle tube matches with a cross-sectional shape of the seat post. 
     
     
         9 . The built-in battery device of the electric bicycle according to  claim 8 , wherein an upper end of the middle tube is provided with a vertical notch ( 71 ), and a retaining ring locking device is arranged at the notch. 
     
     
         10 . The built-in battery device of the electric bicycle according to  claim 1 , wherein the battery pack is connected to a controller through wires.